Freediving, also known as breath-hold diving, is a recreational sport and competitive activity where divers descend and ascend underwater, relying solely on their ability to hold their breath. While freediving allows people to experience the tranquility and beauty of the underwater world, it carries certain risks, especially that of barotrauma injuries.
What is Barotrauma?
Barotrauma refers to injuries caused by pressure differences between the inside and outside of the body. In freediving, these pressure differences occur during descent and ascent as the ambient water pressure increases and decreases. The air spaces in the body are susceptible to pressure changes and can be injured if adequate equalization is not performed.
Some of the key air spaces in the body at risk of barotrauma during freediving include:
- Ears
- Sinuses
- Lungs
- Gastrointestinal tract
If these air spaces are not equalized properly, they can rupture, collapse, or over-expand, leading to barotrauma injuries.
Common Barotrauma Injuries in Freediving
Some of the most common barotrauma injuries that can occur in freediving include:
Ear Barotrauma
The eardrum separates the external ear from the middle ear cavity. During descent, increasing water pressure can force the eardrum inward, leading to pain, bleeding, and rupture of the eardrum. This is called external ear barotrauma.
Alternatively, inadequate equalization during ascent can lead to negative pressure building up in the middle ear, causing internal ear barotrauma. This can lead to edema and hemorrhage of middle ear structures.
Symptoms of ear barotrauma include vertigo, tinnitus, muffled hearing, and otalgia.
Sinus Barotrauma
The sinus cavities in the face also need to be equalized during freediving. Inadequate equalization can lead to negative or positive pressure damage to the sinus mucosa.
Symptoms include pain over the sinus area, epistaxis, and hemorrhage. Damage to the sinus ostia can also cause chronic sinusitis.
Pulmonary Barotrauma
As ambient pressure increases during descent, the air in the lungs also gets compressed to a smaller volume. During ascent, if air is held in the lungs, then the lungs can overexpand as ambient pressure decreases.
This can lead to extra-alveolar air rupturing through the parenchyma into the pleural space, arterial circulation, and mediastinum. Symptoms include chest pain, dyspnea, hypoxemia, and cardiovascular collapse.
Gastrointestinal Barotrauma
The gastrointestinal tract can also be affected by pressure changes in freediving. Gas expansion can lead to gastric distention, gastric hemorrhage, or gastric rupture. Intestinal ischemia can also occur from mesenteric arterial gas embolization.
Symptoms include nausea, vomiting abdominal pain and distension, and bloody stools.
Risk Factors for Barotrauma Injuries
Certain factors can increase a freediver’s risk of developing barotrauma:
- Inadequate equalization – Improper or inadequate equalization during descent and ascent is the major risk factor. This can be due to poor equalization technique, anatomical variations, or health conditions.
- Rapid pressure change – Quick descents and ascents increase risk as there is insufficient time to equalize pressures.
- Repetitive diving – Repeated diving with short surface intervals can increase risk due to inadequate gas elimination.
- Preexisting health conditions – Conditions like asthma, previous barotrauma, and respiratory infections can increase susceptibility.
- Depth and duration – Deeper and longer freedives are associated with greater pressure changes and barotrauma risk.
- Equipment – Poor fitting masks, unsuitable fins, and heavy weights can contribute by causing rapid ascents/descents.
Preventing Barotrauma Injuries in Freediving
Barotrauma injuries can be minimized by taking certain precautions:
- Learn proper equalization techniques such as the Valsalva maneuver, Frenzel maneuver, and Toynbee maneuver. Equalize early and frequently during descent and ascent.
- Ascend and descend slowly at a rate of 10-30 feet per minute.
- Use a buoyancy control device to avoid overly rapid ascents.
- Limit dive depth and duration to your experience level and training.
- Refrain from freediving when congested or with a respiratory infection.
- Ensure equipment like masks, fins, and weights are appropriately fitted for you.
- Maintain surface intervals of >2 minutes between repetitive dives.
- Stay properly hydrated before and after dives.
- Seek medical advice if you have a history of lung disease like asthma.
Diagnosis and Treatment of Barotrauma
If barotrauma is suspected after diving, prompt medical evaluation is required. Diagnosis is based on history and clinical examination. Investigations like x-rays, CT scans and tympanometry may be done to assess for injuries.
Mild cases can be managed by observation and pain control. Severe cases may require interventions like chest tube insertion for pneumothorax, nasal packing for epistaxis, or surgery to repair perforated eardrums or visceral ruptures. Antibiotics, steroids, and decongestants may also be prescribed.
Overall, barotrauma can be avoided with safe diving practices. Freedivers should be aware of risk factors and preventive measures to enjoy the sport safely. With proper equalization and pressure control, the risk of barotrauma injuries in freediving can be significantly reduced.
